It's an interesting thought that, since it was recognised before the last election that the winner would only serve one term, and (wasn't it the governor of the Bank of England who said this) then be unelectable for a generation. I wonder if the torys were happy with a coalition as the result. Labour certainly didn't seem serious about forming a coalition at the time.

Incidentally I'm not trying to excuse the Lib Dems for their performance in government (although we could have had a better electoral system out of it, which would almost have been worth it) personally I think the odds are a little generous in their favour!

The uncertain areas I see in the run up to a 2015 election are:
If the lib dem vote collapses completely this might have the effect of reunifying the left
If Scotland votes for independence, we'll loose 60 none conservative MP's. That could well significantly shift the balance of power
Could one of the anti-european parties split the right?

A lot of water to go under the bridge and a lot of ifs there but its certainly going to be interesting.

Are these about right and will they have changed after the party conferences?

Even before they committed political suicide by joining the current coalition, 100/1 for the Lib Dems to be the largest party after a General Election would have been mean odds. I think the bookies could safely offer odds of 10,000,000/1 on it happening now and be safe in the knowledge they wouldn't lose a penny if anyone was daft enough to take the bet on.

As for which of Labour or the Tories will win most seats next time, I think it is impossible to say at the moment. Labour are polling well right now, but oppositions often poll well in mid term and then fail to win the subsequent election. Pollsters tell us the Tories ratings would change overnight for the better if they somehow managed to replace David Cameron with Boris Johnson, regardless that their policy differences are minimal. That's how fickle polls (and the voting public) can be and the Tory party has quite a record for dumping unpopular leaders!

Ultimately it will hang on the state of the economy in 2015. Will voters want to punish the incumbents for making a bad situation worse, or reward them if things are looking up by then.

The only thing we do know with certainty is that the number of seats both parties receive will be a gross distortion of the actual number of votes they get, and whoever wins the most seats or even an outright majority of them will not have polled anywhere near 50% of the popular vote. But the chance to do anything about that was blown earlier this Parliament.